JP4136781B2 - Sheet storage device and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet storage device and an image forming apparatus, and more particularly, to a sheet storage device and an image forming apparatus provided with a plurality of urging means for urging an intermediate plate provided in a sheet storage portion so as to be movable in the vertical direction toward the sheet feeding means.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in image forming apparatuses such as printers, facsimiles, copiers, and the like, a sheet feeding cassette as a sheet storage device is detachably attached to the apparatus main body, and is stored in this sheet feeding cassette at the time of image formation. There is one in which a sheet is fed to an image forming unit by a sheet feeding device.
[0003]
FIG. 9 shows the configuration of such a conventional sheet feeding apparatus. In FIG. 9, reference numeral 1 denotes a paper feed cassette. Here, the sheet feeding cassette 1 is detachably disposed on the apparatus main body, and when setting the sheet S, the sheet S is stacked after being pulled out from the apparatus main body in the direction of arrow A.
[0004]
Reference numeral 3 denotes a sheet feeding roller which is provided in the apparatus main body and is a sheet feeding means for feeding the sheet S by frictional force. The sheet feeding roller 3 is cut out at a part of its peripheral surface and only during sheet feeding. It is controlled to make one counterclockwise rotation. Reference numeral 50 denotes an intermediate plate that is supported by the paper feed cassette 1 so as to be pivotable in the vertical direction, and is loaded with a predetermined pressure toward the paper feed roller 3 by a spring 151. Has been.
[0005]
Reference numeral 2 denotes a separation pad that is in pressure contact with the paper feed roller 3. The separation pad 2 is rotatably supported by the paper feed cassette 1 and is attached to the paper feed roller 3 by a spring 20 with a predetermined pressure. Affixed to the holder 2a. A sheet feeding roller 30 is disposed coaxially with the sheet feeding roller 3 so as to be rotatable. The sheet feeding roller 30 is a standby position where the sheet feeding roller 3 faces the sheet S with the notch 3a shown in FIG. The sheet S and the separation pad 2 are in contact with each other when stopped.
[0006]
In the sheet feeding apparatus having such a configuration, when the sheet feeding roller 3 rotates, the sheet S is fed toward the nip portion with the separation pad 2 by a frictional force with the sheet feeding roller 3.
[0007]
At this time, there are cases where a plurality of sheets S are fed toward the nip portion due to the frictional force between the sheets. At the nip portion, the second and subsequent sheets S are stopped by the separation pad 2 having a higher friction coefficient than the sheet S, and a strong conveying force is applied by contacting the sheet feeding roller 3 having a higher friction coefficient than the separation pad 2. Only the uppermost sheet S 1 is fed to the conveying roller 4.
[0008]
After the sheet has been fed to the conveying roller 4 in this way, the sheet feeding roller 3 stops at a standby position where the notch 3a faces the sheet S as shown in FIG. It is conveyed to the illustrated image forming unit.
[0009]
By the way, in such a sheet feeding apparatus in which the intermediate plate 50 is urged so that the sheet S on the intermediate plate is brought into pressure contact with the sheet feeding roller 3, depending on the basis weight or size of the sheet S, the sheet S and the sheet S are fed. Variations in the sheet feeding pressure with the paper roller 3 cause a decrease in sheet feeding performance such as non-feeding and double feeding.
[0010]
For example, when A4 and letter size large sheets (hereinafter referred to as large size sheets) and A5 and B5 size small sheets (hereinafter referred to as small size sheets) are stacked in the same number, Since the weight is light, when the same spring 151 urges the sheet feeding roller 3 toward the sheet feeding roller 3, the sheet feeding pressure increases, and double feeding is likely to occur.
[0011]
On the other hand, if the biasing force of the spring 151 is lowered so that double feeding does not occur in a small-size sheet, if the large-size sheet is biased toward the paper feed roller 3, the paper feed pressure becomes low, which causes non-feeding. Become. In particular, the variation tends to increase as the capacity of the sheet feeding cassette 1 increases.
[0012]
Therefore, in order to suppress such variations in the sheet feeding pressure, a plurality of urging means such as a spring for urging the middle plate are provided in the sheet feeding cassette 1. For example, when a small size sheet is stacked, a user can connect a lever or a dial. A mechanism is used that reduces the sheet feeding pressure of a small-sized sheet that normally increases by holding some of the plurality of urging means in a non-operating state by operation.
[0013]
However, in the paper feed cassette 1 having such a mechanism that the user operates the lever and the dial, when the user does not set the lever or the dial to an appropriate position when the sheets are stacked, a target paper feed pressure can be obtained. Therefore, there is a possibility that the paper feeding performance such as non-feeding and double feeding is deteriorated.
[0014]
As another sheet feeding cassette 1 for suppressing variation in sheet feeding pressure, a plurality of urging means for urging the intermediate plate are provided, and side regulation for regulating the position in the width direction perpendicular to the sheet feeding direction. A proposal has been made to stabilize the paper feed pressure by keeping some of the plurality of urging means in a non-operating state in conjunction with the movement of the plate (see Patent Document 1).
[0015]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-41187
[0016]
[Problems to be solved by the invention]
However, in a conventional paper feed cassette having a mechanism that adjusts the paper feed pressure in conjunction with such a side regulating plate, it is indispensable for the user to operate the side regulating plate after pushing down the middle plate. If this is neglected, the sheet feeding pressure is not optimized, and there is a possibility that sheet feeding performance such as non-feeding and double feeding will be deteriorated.
[0017]
If the user forgets to operate the lever or dial, the cause can be understood by looking at the lever or dial. However, the operation of the side regulating plate is essentially an operation for regulating the side edge position of the seat. When the user forgets to operate the side restriction plate and a paper feed failure occurs, there is a problem that it is difficult for the user to understand the cause.
[0018]
In other words, when adjusting the paper feed pressure in conjunction with the side restricting plate, not only is an additional operation imposed on the user, but a stable paper feed performance is demonstrated if the user forgets the operation. There is a problem that you can not.
[0019]
Therefore, the present invention has been made in view of such a current situation, and provides a sheet storage device and an image forming apparatus that can exhibit stable paper feeding performance without requiring a user to perform a special operation. It is for the purpose.
[0020]
[Means for Solving the Problems]
The present invention includes a sheet storage unit that is detachably attached to the image forming apparatus main body and stores sheets, a middle plate that is provided in the sheet storage unit and is movable in a vertical direction on which the sheets are stacked, A sheet storage device comprising movable side regulating means for regulating the position of the side edge in the width direction perpendicular to the sheet feeding direction of the sheets stacked on the middle plate, wherein the middle plate is placed in the image forming apparatus main body. A plurality of urging means for urging toward the provided sheet feeding means, and the middle plate lowered against the urging force of the plurality of urging means when pulled out from the image forming apparatus main body; The intermediate plate urging operation is selected as a predetermined urging means among the plurality of urging means in conjunction with the stopper member that is held in a state and the movement of the side restricting means to the side end restricting position according to the sheet size. Energizing action control And when the intermediate plate is held by the stopper member, the urging operation control means moves the side regulating means to a position for regulating the side edge of a large sheet. Is moved to a first position for causing the predetermined urging means to perform an intermediate plate urging operation, and when the side restricting means is moved to a position for restricting a side edge of a small sheet, the predetermined urging means is used. It moves to the 2nd position which controls middle board energizing operation.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0022]
FIG. 2 is a diagram illustrating a schematic configuration of a laser beam printer which is an example of an image forming apparatus including the sheet storage device according to the embodiment of the present invention.
[0023]
In FIG. 1, reference numeral 100 denotes a laser beam printer. The laser beam printer 100 includes an image forming unit 101 that forms an image, a sheet feeding device 102 that separates and feeds sheets S one by one to the image forming unit 101, and the like. It has.
[0024]
The image forming unit 101 includes a process cartridge 70 that can be attached to and detached from a laser beam printer main body (hereinafter referred to as an apparatus main body) 100A, a transfer roller 6, and the like. The process cartridge 70 includes a photosensitive drum 7, a charging roller 9, a developing unit 10, a cleaning unit (not shown), and the like.
[0025]
The sheet feeding apparatus 102 includes a sheet feeding cassette 1 that is a sheet storing unit for stacking and storing sheets, a sheet feeding roller 3 that is a sheet feeding unit having a substantially half-moon shape with a part of the peripheral surface cut away, and a spring. 20 is provided with a separation pad 2 that is urged toward the paper feed roller 3 with a predetermined pressure by 20 and forms a nip with the paper feed roller 3.
[0026]
The paper feed cassette 1 includes an intermediate plate 50 that is pivotable (movable) in the vertical direction about a shaft 50a. The intermediate plate 50 is mounted on the apparatus main body 100A. The sheet S is raised to a sheet feedable position where the sheet S is pressed against the sheet feed roller 3 with a predetermined pressure by a spring described later.
[0027]
In the figure, reference numeral 22 denotes a laser scanner unit, 15 denotes a fixing device, and 18 and 19 denote a pair of discharge rollers for discharging the sheet S to the discharge tray 21.
[0028]
Next, an image forming operation of the laser beam printer 100 configured as described above will be described.
[0029]
A plurality of sheets S stacked in the sheet feeding cassette 1 are pushed up by the intermediate plate 50 toward the sheet feeding roller 3 with a predetermined pressure.
[0030]
When image information is sent from a personal computer (not shown) and a control unit (not shown) that performs image formation processing of this image information issues a print signal, the paper feed roller is controlled to rotate counterclockwise only during paper feeding. 3 rotates, and the sheet S stacked in the sheet feeding cassette 1 is sent to the image forming unit 101. When a plurality of sheets S enter the nip portion between the paper feed roller 3 and the separation pad 2, only the uppermost sheet S 1 is sent to the image forming unit 101 by the action of the separation pad 2.
[0031]
On the other hand, laser light is irradiated onto the photosensitive drum from the laser scanner unit 22 based on the image information together with this print command, whereby a latent image is formed on the surface of the photosensitive drum 7. Further, the latent image is developed by the developing device 10 to form a toner image on the photosensitive drum.
[0032]
The toner image thus formed on the photosensitive drum is then transferred to the sheet S sent to the nip portion between the photosensitive drum 7 and the transfer roller 6 by the conveying rollers 4 and 5. Further, the sheet S on which the toner image is transferred is sent to the fixing device 15, and is guided to the nip portion between the heating unit 13 of the fixing device 15 and the pressure roller 14 in pressure contact therewith, and passes through the nip portion. The toner image transferred to the sheet surface is heated and pressurized and fixed on the sheet surface. Thereafter, the sheet that has passed through the fixing device 15 is conveyed by a pair of discharge rollers 18 and 19 and discharged onto the discharge tray 21.
[0033]
FIG. 3 is a side view of the paper feed cassette 1 according to the present embodiment. In FIG. 3, reference numeral 11 denotes a side plate constituting the side wall surface of the sheet storage portion 1 </ b> A (see FIG. 2) of the paper feed cassette 1. Reference numeral 50a denotes a protruding portion that protrudes in the width direction from both side ends of the front end portion of the sheet feeding direction of the intermediate plate 50. This protruding portion 50a protrudes from the opening 11a provided on the side plate 11 to both sides of the cassette. ing. As a result, the intermediate plate 50 rotates in the vertical direction about the shaft 50b as a fulcrum while being guided by the opening 11a and the protrusion 50a.
[0034]
Reference numeral 31 denotes a pushing rib provided on the apparatus main body 100A. When the paper feeding cassette 1 is pulled out from the apparatus main body 100A, the pushing rib 31 protrudes from the side plate 11 to both side surfaces of the cassette 50 ( (Hereinafter referred to as a middle plate protrusion) 50a.
[0035]
Here, the pushing rib 31 has an inclined surface 31a inclined downward in the sheet feeding direction. When the sheet feeding cassette 1 is pulled out, first, the intermediate plate protrusion 50a is formed on the inclined surface 31a of the pushing rib 31. After that, the intermediate plate 50 is rotated downward about the shaft 50b while being guided by the pushing rib 31.
[0036]
Reference numeral 33 denotes an intermediate plate stopper which is a stopper member which is rotatably held on the side plate 11 with the shaft 33b as a fulcrum. When the paper feeding cassette 1 is pulled out, the intermediate plate protrusion 50a of the intermediate plate 50 rotated downward is engaged. By stopping, the intermediate plate 50 is held at a position rotated downward. The intermediate plate stopper 33 rotates in contact with the release rib 32 provided on the apparatus main body 100A when the paper feed cassette 1 is mounted on the apparatus main body 100A, and engages the intermediate plate protrusion 50a. The nail | claw part 33a of the intermediate | middle board stopper 33 to stop will be in the state retracted | saved from the locus | trajectory of the intermediate | middle board protrusion part 50a.
[0037]
Next, the operation of the intermediate plate 50 and the intermediate plate stopper 33 when the paper feed cassette 1 is attached / detached will be described with reference to FIGS.
[0038]
FIG. 3A shows a state where the paper feed cassette 1 is mounted on the apparatus main body 100A. In this state, the intermediate plate 50 is urged toward the paper feed roller 3 by first to third springs shown in FIG. The middle plate stopper 33 is in contact with the release rib 32, and the claw portion 33a of the middle plate stopper 33 is retracted from the locus of the middle plate protrusion 50a.
[0039]
Here, when the sheet feeding cassette 1 is pulled out in the right direction in the drawing, as shown in FIG. 3B, the middle plate 50 (the middle plate protrusion 50a) comes into contact with the pushing rib 31 provided in the apparatus main body 100A. Then, it is guided downward by the pushing rib 31 and pushed down.
[0040]
After that, when the sheet feeding cassette 1 is further pulled out, first, the intermediate plate stopper 33 and the release rib 32 are separated from each other as shown in FIG. It rotates clockwise by an urging force of a spring (not shown) and stops at a predetermined position.
[0041]
Next, as shown in FIG. 4B, when the contact between the intermediate plate 50 (the intermediate plate protrusion 50a) and the pushing rib 31 is released, the intermediate plate 50 is pushed upward by a spring, The intermediate plate stopper 33 is held when the intermediate plate protrusion 50a is engaged. Therefore, when the user pulls out the sheet cassette 1, the intermediate plate 50 is held by the intermediate plate stopper 33 at a pushed-down position as shown in FIG.
[0042]
On the other hand, when the paper cassette 1 is inserted into the apparatus main body 100A when the paper cassette 1 is pushed into the apparatus main body, the intermediate plate 50 is held by the intermediate plate stopper 33 as shown in FIG. Then, as shown in (a) of FIG. Here, when the intermediate plate 50 is pushed down in this way, the force of the intermediate plate 50 does not act on the intermediate plate stopper 33, so that the intermediate plate stopper 33 can be rotated with a small force.
[0043]
When the sheet feeding cassette 1 is further pushed in this state, the middle plate stopper 33 contacts the release rib 32 and rotates counterclockwise as shown in FIG. The 33 claw portions 33a are retracted from the locus of the middle plate protrusion 50a. As a result, when the sheet feeding cassette 1 is further pushed in, the intermediate plate 50 rises along the inclined surface 31a of the pushing rib 31 by the biasing force of the spring. The intermediate plate 50 is in contact with the paper feed roller 3 at a position where the paper feed cassette 1 is completely mounted.
[0044]
3 and 4, the sheets are not stacked on the intermediate plate, but the same operation is performed even when the sheets are stacked. In this case, when the sheet feeding cassette 1 is mounted, the uppermost layer is operated. The sheet is in contact with the sheet feed roller 3.
[0045]
FIG. 1 is a perspective view of the sheet feeding cassette 1. In FIG. 1, reference numerals 66 and 67 are provided so as to be movable in the width direction, and regulate the position of sheets (bundles) placed on the intermediate plate 50. A pair of side regulating plates 39, which are side regulating means, are rear end regulating plates that regulate the rear end of the sheet. In the present embodiment, the side regulating plates 66 and 67 are configured such that when one is moved by the pinion gear 38 and a rack (not shown), the other is also moved.
[0046]
Reference numeral 52 denotes a second spring that urges the intermediate plate 50, and reference numerals 51 a and 51 b denote first and third springs that are arranged on both sides of the second spring 52 in the width direction and urge the intermediate plate 50. Reference numeral 61 denotes a spring cap attached to the upper surface of the second spring 52, and 62 denotes a spring lock member. By engaging and disengaging the spring lock member 62 with respect to the spring cap 61, the urging force of the second spring 52 is selectively selected as a middle plate. The second spring 52 is selectively made to perform the middle plate urging operation.
[0047]
The spring lock member 62, which is an urging operation control means, is held in the sheet feeding cassette 1 so as to be movable in the sheet feeding direction. ) Is pulled by the tension spring 63 and stopped at a predetermined position.
[0048]
By the way, the inclined surface 66a is provided at the front end of the one side restricting plate 66 in the moving direction, and the inclined end of the side restricting plate 66 is provided at the end of the spring lock member 62 facing the front end of the one side restricting plate 66 in the moving direction. An inclined surface 62a that contacts the surface 66a is provided.
[0049]
When the side regulating plates 66 and 67 are aligned with the large size sheet as shown in the figure, the inclined surface 66a of one of the side regulating plates 66 is at a position separated from the inclined surface 62a of the spring lock member 62. . At this time, the spring lock member 62 is in a position retracted from the locus of the second spring 52 and the spring cap 61.
[0050]
Here, in such a state, the spring lock member 62 does not lock the second spring 52, that is, the spring lock member 62 causes the second spring 52, which is a predetermined biasing means, to perform the middle plate biasing operation. Therefore, when the paper feed cassette 1 is mounted in the apparatus main body, the three springs 51a, 51b, 52 as a plurality of urging means are all extended as shown in FIG. The middle plate 50 is pushed upward by the three springs 51a, 51b, 52, and can generate a relatively large sheet feeding pressure.
[0051]
When storing a large sheet in this way, by generating a relatively large sheet feeding pressure, the large sheet can be reliably conveyed without causing non-feeding, resulting in a decrease in sheet feeding performance. Can be prevented.
[0052]
On the other hand, as shown in FIG. 5, when the side regulating plates 66 and 67 are moved according to the small size sheet (B5 or smaller size), the inclined surface 66a of the one side regulating plate 66 is the same as the inclined surface 62a of the spring lock member. It abuts and pushes the spring lock member 62 toward the spring cap 61 while resisting the tension spring 63.
[0053]
Here, as described above, when the paper feed cassette 1 is removed from the apparatus main body 100A, the intermediate plate 50 is rotated downward, and when the intermediate plate 50 is rotated downward as described above, as shown in FIG. The three springs 51a, 51b, 52 are in a contracted state. When the spring lock member 62 is pushed out in this state, the spring lock member 62 enters the groove portion 61a provided in the spring cap 61 that is an engaging member. That is, when one side regulating plate 66 is moved, the spring lock member 62 is moved to the second position that regulates the middle plate biasing operation of the second spring 52.
[0054]
As a result, when the paper feed cassette 1 is subsequently attached to the apparatus main body 100A, the second spring 52 is locked in a compressed state by the spring lock member 62, so that the intermediate plate 50 has two springs 51a as shown in FIG. , 51b are pushed upward to generate a relatively low sheet feeding pressure.
[0055]
And, when storing small size sheets in this way, by generating a relatively small sheet feeding pressure, the small size sheets can be reliably conveyed without causing non-feeding, resulting in a decrease in sheet feeding performance. Can be prevented.
[0056]
When storing a large-sized sheet, first, as described above, the paper feed cassette 1 is pulled out from the apparatus main body 100A. At this time, since the intermediate plate 50 is held at the pushed-down position as shown in FIG. 6, when the side regulating plates 66 and 67 are moved to the position shown in FIG. The pressing of the member 62 is released.
[0057]
Thereby, the spring lock member 62 is pulled by the tension spring 63 and moves from the second position to the first position, and as a result, the lock of the second spring 52 by the spring lock member 62 is released. The spring lock member 62 is moved to the first position or the second position in conjunction with the movement of the side restriction plates 66 and 67 by the inclined surface 66a of the one side restriction plate 66, the inclined surface 62a of the spring lock member 62, and the tension spring 63. A moving means for moving to a position is configured.
[0058]
Here, as shown in FIG. 6, when the intermediate plate 50 is in the depressed position, the spring lock member 62 is not in contact with the spring cap 61. Therefore, the movement of the spring lock member 62 is performed with a small force. This can be performed, and the force acting in the direction that hinders the operation of the side regulating plates 66 and 67 can be reduced. As a result, the influence on the operation of the side regulating plates 66 and 67 is reduced, and the side regulating plates 66 and 67 can be operated smoothly.
[0059]
As described above, when the sheet feeding cassette 1 is pulled out, when the intermediate plate 50 is held in the lowered state, the spring lock is interlocked with the movement of the side regulating plate 66 to the position for regulating the side edge of the large size sheet. By moving the member 62 to the first position and moving the spring lock member 62 to the second position in conjunction with the movement of the side regulating plate 66 to the position where the side edge of the small size sheet is regulated, the user can Without any special operation, it is possible to suppress variations in sheet feeding pressure and to exhibit stable sheet feeding performance.
[0060]
That is, the user simply pulls out the paper feed cassette 1 from the apparatus main body 100A and adjusts the side regulating plates 66 and 67 to the sheet size. The size sheet can be switched to a smaller size, thereby preventing occurrence of double feed, non-feed, etc. without affecting usability, and improving paper feed performance.
[0061]
Next, a second embodiment of the present invention will be described.
[0062]
FIG. 7 is a diagram illustrating the configuration of the paper feed cassette 1 according to the present embodiment. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.
[0063]
In the figure, 76 and 77 are a pair of side restricting plates that can move in the width direction. When the pair of side restricting plates 76 and 77 are moved by a rack (not shown) and the pinion gear 38, the other is also the other. It is configured to move.
[0064]
Reference numeral 72 denotes a spring lock member, and reference numeral 71 denotes a spring cap attached to the upper surface of the second spring 52. The spring lock member 72 is rotatably held by the paper feed cassette 1 with a shaft 72b as a fulcrum. This figure shows a state in which the side regulating plates 76 and 77 are aligned with the large size sheet. In this state, the moving direction front end portion 76a of one side regulating plate 76 is provided on the spring lock member 72. It is in a position separated from the locking portion 72a.
[0065]
When the moving direction front end portion 76a of the one side regulating plate 76 is in a position separated from the locking portion 72a in this way, the spring lock member 72 is pulled by the tension spring 73, and the middle plate spring 52 and the spring cap 71 are Stops at a predetermined position retracted from the trajectory.
[0066]
In this state, since the spring lock member 72 is in the first position where the second spring 52 is not locked, the three springs 51a, 51b, 52 are mounted when the paper feed cassette 1 is mounted in the apparatus main body. As shown in the figure, all of them are in an extended state, whereby the middle plate 50 (not shown) is pushed upward by the three springs 51a, 51b, 52, and generates a relatively large sheet feeding pressure. Thereby, a large-sized sheet can be reliably conveyed without causing non-feeding, and a decrease in paper feeding performance can be prevented.
[0067]
On the other hand, as shown in FIG. 8, when the side regulating plates 76 and 77 are moved to a position aligned with the small size sheet, the leading end portion 76a of the one side regulating plate 76 contacts the locking portion 72a of the spring lock member 72. Thus, the spring lock member 72 rotates toward the spring cap 71 and enters the groove 71a (see FIG. 7) provided in the spring cap 71. That is, the spring lock member 72 moves to the second position as the one side regulating plate 76 moves.
[0068]
As a result, when the paper feed cassette 1 is subsequently attached to the apparatus main body 100A, the second spring 52 is locked in a compressed state by the spring lock member 72 moved to the second position, so that the intermediate plate is as shown in FIG. The two springs 51a and 51b are pushed upward to generate a relatively small sheet feeding pressure. Thus, in the case of a small size sheet, by generating a relatively small sheet feeding pressure, it is possible to reliably convey the small size sheet without causing double feeding, thereby preventing a decrease in sheet feeding performance. be able to.
[0069]
On the other hand, when storing a large-sized sheet, first, the sheet feeding cassette 1 is pulled out from the apparatus main body 100A as described above. At this time, since the intermediate plate 50 is held at the pushed-down position as shown in FIG. 6, when the side regulating plates 76 and 77 are moved to the position shown in FIG. 72 is released.
[0070]
Thereby, the spring lock member 72 is pulled by the tension spring 73 and moves from the second position to the first position. As a result, the lock of the second spring 52 by the spring lock member 72 is released. The spring lock member 72 is moved to the first position or the first position in conjunction with the movement of the side restricting plates 76 and 77 by the front end 76a of one side restricting plate 76, the engaging portion 72a of the spring lock member 72, and the tension spring 73. A moving means for moving to two positions is configured.
[0071]
Since the spring lock member 72 is not in contact with the spring cap 71 when the intermediate plate 50 is in the depressed position as shown in FIG. 6 described above, the spring lock member 72 also rotates. Since the sliding resistance is small, the spring lock member 72 can be moved with a small force, and the force acting in the direction that hinders the operation of the side regulating plates 76 and 77 can be reduced.
[0072]
In this way, the user can pull out the paper feed cassette 1 from the apparatus main body 100A and perform the normal operation of adjusting the side regulating plates 76 and 77 to the sheet size. The small-size sheet can be switched so as to weaken, thereby preventing the occurrence of double feeding, non-feeding, etc. without affecting usability and improving the paper feeding performance.
[0073]
In the description so far, the side regulating plate has been described as an example in which one side is moved when the other is moved. However, the present invention is not limited to this, and the side edge regulation of the sheet is limited. Needless to say, the present invention can also be applied to a paper feed cassette that is configured by two side regulating plates and a fixed wall.
[0074]
In the above description, the case where the middle plate is urged by three springs has been described. However, the present invention is not limited to this, and the number of springs may be at least two. Further, the spring locked by the spring lock member is not limited to one spring at the center, and other springs may be locked.
[0075]
【The invention's effect】
As described above, as in the present invention, the urging operation control means for selectively causing the predetermined urging means of the plurality of urging means to perform the middle plate urging operation is interlocked with the movement of the side restricting means. By moving to a first position where the predetermined urging means performs the middle plate urging operation or a second position where the middle urging operation of the predetermined urging means is restricted, the user can perform a special operation. Therefore, stable paper feeding performance can be exhibited.
[Brief description of the drawings]
FIG. 1 is a perspective view of a sheet feeding cassette which is a sheet storage device according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a schematic configuration of a laser beam printer as an example of an image forming apparatus in which the paper feed cassette is detachably mounted.
FIG. 3 is a first diagram illustrating the operation of an intermediate plate and an intermediate plate stopper when the paper feed cassette is attached / detached.
FIG. 4 is a second diagram illustrating the operation of the middle plate and the middle plate stopper when the paper feeding cassette is attached / detached.
FIG. 5 is a perspective view illustrating a state when a small size sheet is stored in the sheet feeding cassette.
FIG. 6 is a cross-sectional view illustrating a state when a small size sheet is stored in the sheet feeding cassette.
FIG. 7 is a perspective view of a sheet feeding cassette which is a sheet storage device according to a second embodiment of the present invention.
FIG. 8 is a perspective view illustrating a state when a small size sheet is stored in the sheet feeding cassette.
FIG. 9 is a diagram illustrating a configuration of a conventional sheet feeding apparatus.
[Explanation of symbols]
1 Paper cassette
1A Sheet storage
3 Feed roller
31 Push-in rib
31a Inclined surface of pushing rib
33 Middle plate stopper
50 Middle plate
66, 67 Side regulating plate
51a First spring
51b Third spring
52 Second spring
61 Spring cap
62 Spring lock member
71 Spring cap
72 Spring lock member
76, 77 Side regulating plate
100 Laser beam printer
100A main unit
101 Image forming unit
102 Sheet feeding device
S sheet

Claims (6)

A sheet storage unit that is detachably attached to the image forming apparatus main body and stores sheets, a middle plate that is provided in the sheet storage unit and is movable in the vertical direction on which the sheets are stacked, and a stack on the middle plate In a sheet storage device comprising movable side regulating means for regulating the position of the side edge in the width direction perpendicular to the sheet feeding direction of the sheet that has been made,
A plurality of biasing means for biasing the intermediate plate toward a sheet feeding means provided in the image forming apparatus main body;
A stopper member that holds the intermediate plate in a lowered state against the urging force of the plurality of urging means when pulled out from the image forming apparatus main body;
Energizing operation control for selectively causing an intermediate plate energizing operation to be performed by a predetermined energizing unit among the plurality of energizing units in conjunction with the movement of the side regulating unit to the side end regulating position according to the sheet size. Means,
With
The biasing operation control means is configured to perform the predetermined biasing when the side regulating means is moved to a position for regulating a side edge of a large sheet when the intermediate plate is held by the stopper member. When the side restricting means is moved to a position for restricting the side edge of the small sheet, the intermediate plate energizing operation of the predetermined energizing means is performed. A sheet storage device that moves to a second position to be regulated. 2. The sheet storage apparatus according to claim 1, further comprising a moving unit that moves the urging operation control unit to the first position or the second position in conjunction with the movement of the side regulating unit. 3. The predetermined biasing means is provided with an engaging member that engages with the biasing operation control means when the biasing operation control means moves to the second position. The sheet storage device described. The urging operation control means moves to the first position or the second position in a non-contact state with the engaging member when the intermediate plate is held by the stopper member. 3. The sheet storage device according to 3. When pulled out from the image forming apparatus main body, the intermediate plate descends against the urging force of the plurality of urging means along an inclined surface provided in the image forming apparatus main body, and then is moved to the stopper member. When being held and attached to the image forming apparatus main body, the biasing means including the predetermined biasing means or excluding the predetermined biasing means after the locking by the stopper member is released The sheet storage device according to any one of claims 1 to 4, wherein the sheet storage device is raised by an urging force of the means. An image forming unit, the sheet storage device according to any one of claims 1 to 5, and a sheet feeding device for feeding a sheet stored in the sheet storage device to the image forming unit. An image forming apparatus.

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